WHEAT FLOUR
Wheat flour is the most important ingredient in the bakeshop. It provides bulkand structure to most of the baker’s products, including breads, cakes, cookies,and pastries.While the home cook depends almost entirely on a product calledall-purpose flour, the professional baker has available a wide variety of flourswith different qualities and characteristics. In order to select the proper flourfor each product and to handle each correctly, you should understand eachtype of flour and how it is milled.
HARD AND SOFT WHEATS
The characteristics of a flour depend on the variety of wheat from which it ismilled, the location in which the wheat is grown, and its growing conditions.Themost important thing for the baker to know is that some wheats are hard and someare soft.Hard wheats contain greater quantities of the proteins called glutenin andgliadin,which together form gluten when the flour is moistened and mixed.You will recall from chapter 1 that gluten development is one of the baker’smajor concerns when mixing doughs and batters. Strong flours—that is, floursfrom hard wheats with high protein content—are used primarily to make breadsand other yeast products.Weak flours—that is,flours from soft wheats with lowprotein content—are important in the production of cakes, cookies, andpastries. Protein content is discussed in more detail later in this section.
Six principal classes of wheat are grown in North America:
1. Hard red wintermThis wheat is grown in large quantities. It has amoderately high protein content and is used primarily for bread flours.The term red in the name refers to the dark color of the bran and husklayers of the wheat berry, not to the interior of the grain, which is white.
2. Hard red springmThis wheat has the highest protein content of NorthAmerican wheats and is an important component of strong bread flours.
3. Hard whitemThis high-protein wheat is grown in small quantities forbread flours.One interesting use for this wheat is for making whole wheatflours that are lighter in color and not as strong in flavor as whole wheatflours from red wheat.
4. Soft whitemThis is a low-protein wheat useful for pastries, cakes,crackers, and other products in which a softer wheat is required.
5. Soft red winter mThis is another low-protein wheat used for cake and
pastry flours.
6. Durum mThis is the hardest of the six wheat classes. It is used primarilyfor spaghetti and other macaroni products.Different varieties are grown in Europe.For example,four principal wheatstrains grown in France—Recital, Scipion, Soissons, and Textel—are softer—that is, lower in protein—than most North American varieties.
THE MILLING OF WHEAT
The wheat kernel consists of three main parts:
1. The bran is the hard outer covering of the kernel.It is present in whole wheatflour as tiny brown flakes, but it is removed in the milling of white flour.
2. The germ is the part of the kernel that becomes the new wheatplant if the kernel is sprouted. It has a high fat content that canquickly become rancid.Therefore, whole wheat flour containingthe germ has poor keeping qualities.
3. The endosperm is the starchy part of the kernel that remainswhen the bran and germ are removed.This is the portion of thewheat kernel that is milled into white flour. Depending on itssource, the wheat endosperm contains about 63 to 73%starch and 7 to 15% protein, plus small amounts of moisture,fat, sugar, and minerals.Until modern roller milling (described below) wasinvented, wheat was made into flour by grinding it betweentwo large stones.Once the grain was ground,it could be siftedto remove some of the bran. This sifting is called bolting.
Bolted flour is lighter in color and finer in texture than wholewheat flour, but of course some of the flavor and nutrientsare removed with the bran and germ. In specialty markets,one can still find stone-ground flour, especially unboltedwhole wheat flour, and other stone-ground meals, such ascornmeal.Modern milling of wheat into flour is accomplished by afairly complex and highly refined system that uses groovedsteel rollers. In what is called the break system, the rollersare set so that the space between them is slightly smaller thanthe width of the kernels, and the rollers rotate at differentspeeds.When the wheat is fed between them, the rollers flakeoff the bran layers and germ and crack the endosperm intocoarse pieces. Approximately 72% of the wheat kernel can beseparated as endosperm and milled into flour. The remaining 28%consists of bran (about 14%), germ (about 3%), and other outer portions called shorts (about 11%).To further understand how milling works, one must understandthat the outer parts of the endosperm—that is, the parts closest to the bran—are higher in protein than the inner parts.When the grain is cracked in the mill,the outer parts break into larger pieces and the inner parts into smaller pieces.In addition, the parts closest to the bran are darker in color than the creamywhite interior of the endosperm. By repeated sifting and breaking, differentgrades of flour can be obtained from one type of wheat. These grades aredescribed in a following section. But first, it is necessary to introduce otherterms and concepts related to flour milling.
Protein Content and Absorption
For a baker, the most important characteristic of flour is its protein content,because the protein content determines how much gluten can be developed.As we have said, the protein content depends primarily on the type of wheatused and its growing conditions. In other words, to make high-protein flour,you must start with high-protein wheat.Second, the milling process affects the protein content of a grade of flour.Remember that the outer portion ofthe endosperm is higher in protein thanthe inner portion. Thus, a flour made from just the inner portion of a highproteingrain will still be a high-protein flour, but it will be lower in proteinthan a flour made from the entire endosperm or from just the outer portions.The protein content of flours available to professional bakers is always
Kernel of wheat
Provided by the Wheat Foods Council
indicated. It may range from about 8% for cake flours to 12% to 13% for breadflour to 14% and up for high-gluten flour.Absorption refers to the amount of water a flour can take up and holdwhile being made into a simple dough, based on a predetermined standarddough consistency or stiffness. It is expressed as a percentage of the weight of flour. Thus, if the absorption ratio of a certain grade of flour is described as60%, this means 60 lb water combined with 100 lb flour would yield a doughof standard consistency. The absorption ratio of water is a function of theprotein content. The higher the protein content of the flour, the more waterit can absorb. Obviously, this is an important consideration for the baker. Shewill have to adjust the water in her bread formulas if she starts using flour of adifferent protein content.
Ash
When bakers are buying flour, they look at two important numbers in theflour’s description: the protein content and the ash content. The ash contentis an indication of the flour’s mineral content. It is determined by burning asample of flour in a controlled environment. The starch and protein, whenburned completely, turn to carbon dioxide gas, water vapor, and other gases,but the minerals do not burn and are left as ash. In general, the higher the ashcontent, the darker the flour. This is because the bran and the outer parts ofthe endosperm contain more minerals than thewhiter, inner portions of theendosperm. Similarly, whole-grain flour is higher in ash than white flour. In conventional baking, bakers like a relatively low ash content because it makeswhiter breads.Today, many artisan bakers of handmade breads look for darkerflour with a higher ash content because it makes breads with a more robust flavor of wheat.Ash content for wheat flours ranges from about 0.3% for white cake flour
to about 1.5% for whole wheat flour.
Extraction
The term extraction can be confusing because it is used in two different ways.As used in this discussion, extraction refers to the amount of flour milled froma given amount of grain. It is expressed as a percentage of the total amount ofgrain. For example, whole wheat flour is said to be 100% extraction because ifyou start with 100 lb grain, you end up with 100 lb whole wheat flour. As asecond example, if a grade of flour is described as 60% extraction, this meansit would take 100 kg whole grain to produce 60 kg of this grade of flour. Theremaining 40% is bran, germ,shorts, and darker, lower grades of flour.Consider a third example. Remember that the endosperm is about 72% ofthe whole grain. A flour milled from the entire endosperm, then, is 72%extraction. This type of flour is called straight flour, described in the nextsection. Here is the point at which the meaning of extraction can beconfusing. The word is occasionally used to refer to percentage of theendosperm rather than percentage of the whole grain. In other words,according to our first definition, straight flour is 72% extraction because 100 lbflour yields 72 lb straight flour. But according to the second definition, straightflour is called 100% extraction because 100 lb wheat endosperm yields 100 lbstraight flour.This may cause difficulty when you are reading other technicalliterature. In sum, you should be aware that the term has two uses.You willneed to determine from the context which definition is being used.In general, high-extraction flours have high ash and low-extraction flourshave low ash.The higher the extraction number, the darker the flour, in mostcases.
Aging and Bleaching
Freshly milled flour is not good for bread making. The gluten is somewhatweak and inelastic, and the color may be yellowish.When the flour is aged forseveral months, the oxygen in the air matures the proteins so they are strongerand more elastic, and it bleaches the color slightly.Aging flour is costly and haphazard, however, so millersmay add smallquantities of certain chemicals to accomplish the same results quickly.
Bromates, added to bread flours,mature the gluten but do not bleach the floura great deal. Chlorine is added to cake flour because not only is it a maturingagent but it also bleaches the flour to pure white.
Enzymes in Flour
A small but important component of wheat flour is a group of enzymes called
diastase.When water is combined with flour,these enzymes break down some
of the starch into sugars that can be acted upon by yeast. If a particular flour is
low in diastase, these enzymes can be added by the miller.
TYPES OF WHEAT FLOUR
The most important North American types of wheat flour can be summarizedas follows. No exact parallels can be made to European flours, which aredescribed later.
Straight flour Straight flour is flour made from the entire endosperm.In the break system of roller milling describedabove, after the bran, germ,and shorts are removed, the endosperm is cracked and sifted several timesto separate different grades of flour. If these grades, or streams, arerecombined,the result is straight flour.Because itcontains the darker partsof the grain as well as the whiter interior, straight flour is darker in color
than the next grade described below.Protein content of straight flour depends on the wheat, but if made
from hard wheat it may contain 13 to 15% protein.Patent flour Patent flour is milled from the inner part of the endosperm,which breaks into finer particles than the part nearer the bran.Patent flour
made from a hard wheat is a strong flour of excellent quality and light,creamy color. When a formula for a conventional bread calls for breadflour, patent flour is usually selected, although a straight flour could alsobe used if a slightly darker bread is acceptable or desired.The extraction rate of patent flour can be varied depending onspecific needs and on the quality of the wheat. Fancy patent, also called
Types of Flour
Flour Protein Ash
Straight flour 13–15% 0.4–0.45%
Patent flour 11–13% 0.35–0.55%
Clear flour 17% 0.7–0.8%
High-gluten flour 14% 0.5%
Cake flour 8% 0.3%
Pastry flour 9% 0.4–0.45%
All-purpose flour 11–11.5% 0.39–4.4%
extra short,is made from only the inner 40 to 60% of the endosperm.Short
patent may contain up to 80% of the endosperm, while long patent
consists of up to 95% of the endosperm.
Patent flours typically range from 11 to 13% protein and 0.35 to 0.55%
ash.
Clear flour The portion of the endosperm left after the patent flour is
removed is called clear flour.This flour comes from the outer parts of the
endosperm and thus is darker in color and higher in protein. Clear flour is
usually separated into more than one grade. First clear is a dark flour, tan
in color, that is often used in rye breads,where its dark color is not noticed
and its high protein content contributes much-needed gluten. Even
though it is dark, it is lighter in color than second clear, which is a lowgrade
flour not usually used in food production.
Clear flour may have a protein content as high as 17% and an ash
content of 0.7 to 0.8%.
High-gluten flour Flour that has an especially high protein content is
sometimes used in hard-crusted breads and in such specialty products as
pizza dough and bagels. It is also used to strengthen doughs made from
flours that contain little or no gluten. See, for example, the formula for
Chestnut Bread on page 117.
A typical high-gluten flour has 14% protein and 0.5% ash.
Cake flour Cake flour is a weak or low-gluten flour made from soft
wheat.It has a very soft,smooth texture and a pure white color. Cake flour
is used for cakes and other delicate baked goods that require low gluten
content.
Protein content of cake flour is approximately 8%, and ash content is
approximately 0.3%.
Pastry flour Pastry flour is also a weak or low-gluten flour, but it is
slightly stronger than cake flour. It has the creamy white color of patent
flour rather than the pure white of cake flour. Pastry flour is used for pie
doughs and for some cookies, biscuits, and muffins.
Pastry flour has a protein content of about 9% and an ash content of
about 0.4 to 0.45%.
European Flour Types
In much of Europe,a grading system based on the ash content is dominant.For
example, the grades T45 and T55 are white wheat flours with low ash for
breads and pastries.T65 includes high-gluten flours, and T80,T110, and T150
are whole wheat flours of increasing darkness. Other flours are included in
this grading system. For example,T170 is dark rye flour.
Bread flours from European wheats are generally lower in protein than
North American bread flours.Typically, they have a protein content of around
11.5%. Some North American mills have begun supplying similar flour for
artisan bread bakers seeking to imitate classic European breads.
Hand Test for Flour Strength
A typical small bakery keeps three white wheat flours on hand: cake flour,
pastry flour, and a bread flour such as patent.You should be able to identify
these three by sight and touch, because sooner or later someone will dump a
bag of flour into the wrong bin or label it incorrectly, and you will need to be
able to recognize the problem.
Bread flour feels slightly coarse when rubbed between the fingers. If
squeezed into a lump in the hand, it falls apart as soon as the hand is
opened. Its color is creamy white.
Cake flour feels very smooth and fine. It stays in a lump when squeezed
in the hand. Its color is pure white.
Pastry flour feels smooth and fine like cake flour and can also be
squeezed into a lump.However, it has the creamy color of bread flour, not
the pure white color of cake flour.
OTHER WHEAT FLOURS
All-purpose flour, seen in retail markets, is not often found in bakeshops.
This flour is formulated to be slightly weaker than bread flour so it can be
used for pastries as well. A professional baker,however,prefers to use flours
formulated for specific purposes, because these give the best results. Allpurpose
flour has a protein content of about 11 to 11.5%.
Self-rising flour is a white flour to which baking powder and,
sometimes, salt has been added. Its advantage is that the baking powder is
blended in uniformly. However, its use is limited by two factors. First,
different formulas call for different proportions of baking powder. No
single blend is right for all purposes. Second, baking powder loses its
aerating or leavening power with time,so the quality of baked goods made
from this flour can fluctuate.
Whole wheat flour is made by grinding the entire wheat kernel,
including the bran and germ.The germ, as you have learned, is high in fat,
which can become rancid, so whole wheat flour does not keep as well as
white flour.
Because it is made from wheat, whole wheat flour contains glutenforming
proteins,so it can be used alone in bread making.(Protein content
is typically 12 to 13%.) However, bread made with 100% whole wheat
flour is heavier than white bread because the gluten strands are cut by the
sharp edges of the bran flakes. Also, the fat from the wheat germ may
contribute to the shortening action.This is one reason why most whole
wheat breads are strengthened with white flour. Another reason is that the
flavor of 100% whole wheat is stronger than many people care for,and the
lighter flavor imparted by a blend of flours is often preferred by
customers.
Bran flour is flour to which bran flakes have been added.The bran may
be coarse or fine, depending on specifications.
OTHER FLOURS, MEALS,
AND STARCHES
RYE FLOUR
Next to white and whole wheat, rye is the most popular flour for bread
making. Although rye flour contains some proteins, these do not form gluten.
Therefore, breads made with 100% rye flour are heavy and dense.To make a
lighter rye loaf, it is necessary to use a mixture of rye and hard wheat flours.
Typical formulas call for 25 to 40% rye flour and 60 to 75% hard wheat flour.
Rye flour is milled much like wheat flour.The lightest rye flours, from the
inner part of the kernel, have a low extraction rate, corresponding to patent
flour. The following grades and types are generally available: Rye flour
Light rye The lightest is nearly white. It has a very fine texture and a
high percentage of starch, with little protein.
Medium rye This is a straight flour, milled from the whole rye grain
after the bran is removed.Thus, it is darker than light rye and has a higher
protein content.
Dark rye Like clear flour milled from wheat, dark rye comes from the
part of the rye grain closest to the bran.Thus, it is darker than other rye
flours and has a lower percentage of fine starch particles.
Rye meal or pumpernickel flour Rye meal is a dark, coarse meal
made from the entire rye grain, including the bran. It looks somewhat like
oatmeal. Rye meal is used for pumpernickel bread and similar specialty
products.
Rye blend This is a mixture of rye flour (generally about 25 to 40%) and
a strong wheat flour, such as clear flour.
MISCELLANEOUS FLOURS
AND MEALS
Products milled from other grains are occasionally used to add variety to baked
goods. These include cornmeal, rice flour, buckwheat flour, soy flour, potato
flour, oat flour, and barley flour.The term meal is used for milled products that
are not as finely ground as flour.
All of these products are normally used in combination with wheat flour
because they do not form gluten.
STARCHES
In addition to flours, other starch products are used in the bakeshop. Unlike
flour, they are used primarily to thicken puddings, pie fillings, and similar
products.The most important starches in dessert production are as follows:
1. Cornstarch has a special property that makes it valuable for certain
purposes. Products thickened with cornstarch set up almost like gelatin
when cooled.For this reason,cornstarch is used to thicken cream pies and
other products that must hold their shape.
2. Waxy maize and other modified starches also have valuable
properties. Because they do not break down when frozen, they are used
for products that are to be frozen. Also, they are very clear when cooked
and give a brilliant, clear appearance to fruit pie fillings.
Waxy maize does not set up firm like cornstarch but rather makes a
soft paste that has the same consistency hot and cold. Thus, it is not
suitable for cream pie fillings.
3. Instant starches are precooked or pregelatinized so they thicken cold
liquids without further cooking.They are useful when heat will damage
the flavor of the product, as in fresh fruit glazes, such as strawberry.
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